Freeciv is a multiuser reimplementation for Unix/X of the famous Microprose game of Civilization. By default, the game is an improved Civ II, but this can be customized; modpacks for near-100% compatibility with Civ I and Civ II are included. Multiuser gameplay is real-time: in each turn, all human players move concurrently. The game is designed to remain fairly playable even on poor network connections. Freeciv can also be played on standalone machines, and its AI players are a good challenge for beginners. The source code comes with the server, two X clients, and non-X clients for MS Windows and Amiga. Freeciv is released under the GNU General Public License. It is maintained by an international team of coders and enthusiasts, and is easily one of the most fun and addictive network games out there.

Risk is a Java version of the classic RISK board
game, with a simple map format, network play,
single player mode, hotseat, map editor, and many more features. It works on all operating systems that
run Java 1.4 or higher.

Arianne is a multiplayer online engine to develop
turn based and real time games. It provides a
simple way of creating games using Python for a
game's description. Marauroa, its server, uses
Java, MySQL, UDP, and Python for hosting dozens of
players.

Scorched 3D is a modernization of the classic DOS game Scorched Earth ("The Mother Of All Games"). It incorporates a lively three dimensional landscape that includes animated jets, naval vessels, water, and even birds, in addition to detailed tanks and projectiles. Other enhancements include LAN and Internet play and music.

TripleA is a clone of the popular board game "Axis & Allies", which is a turn based strategy wargame. TripleA also acts as a game engine allowing creation of custom games with similar mechanics to Axis and Allies. It supports online play, network play, play-by-email, and single player vs AI or hot-seat. It comes with 11 different maps and the option to download more from online repositories. Most games take place during World War II, though there are mods to play other conflicts like the Napoleonic wars, or Lord of the Rings.

Pioneers is a faithful Gtk2 translation of the
excellent board game "Settlers of Catan", with
server-client multiplayer, computer players, and
support for the changes made in the Seafarers of
Catan expansion to the original board game.

Freelords is a rewrite of the well-known Warlords II. It mainly resembles Warlords, but also extends the game, e.g. units have hit points and the save, and configuration files have an easy-to-read XML format.